const message="fdabc21 faBc323 dfABC12 AaaBc32"

//需求1：将message中的abc全部替换成cba,忽略大小写
const newMessage=message.replaceAll(/abc/ig,"cba")
console.log(newMessage)  //ffdcba21 fcba323 dfcba12 Aacba32

//需求2:将字符串中的数字全部删除
const newMessage2=message.replaceAll(/\d+/ig,"")
console.log(newMessage2) //fdabc faBc dfABC AaaBc

